Number of n X n arrays of squares of integers, symmetric under 90 degree rotation, with all rows summing to 12.

A156457

Number of n X n arrays of squares of integers, symmetric under 90 degree rotation, with all rows summing to 12.

Terms

    a(0) =1a(1) =4a(2) =0a(3) =18a(4) =90a(5) =5154a(6) =19368a(7) =2108280a(8) =31103100a(9) =3164432181a(10) =105602337600

External references